Metals-reduction bomb



W. P. KIERNAN Filed April 25, 1928 March 10, 1931.

I INVENTOR WPKmR/vA/v BY 27; kfl ATTORNEY i at IIIIIIIII! WILLIAM Patented Mar. 10, 1931 UNITED STATES" PHILIP KIERNAN, or nAs'r ORANGE, NEW JERSEY, ASSIGNOB .ro wns'r- INGHOUSE LAMP ooMrANY, A CORPOBATIONOF PENNSYLVANIA PATENT. OFFICE METALS-REDUCTION BOMB Application filed A in 25,

A This invention relates to the art o'f metallurgy and relates more particularly to an improvement in methods of and apparatus for reducing refractory metals. as, for example, the calcium-calcium chloride reduction method disclosed by Rentschler and Marden in copending application Serial No. 717,940,

. plication, the reduction of the refractory metal oxide is effected by an alkaline earth metal (calcium). An alkaline earth. metal; halide (calcium chloride) is used as a fluxing medium for promoting the continuation of thereduction reaction to completion. One of the features of this reduction is that at the temperature of the reduction 950 C. the reaction mass is very fluid and the more fluid Y the mass the more complete the reduction of the refractory metal oxide. In this state of fluidity the corrosive property of the halide flux is at the maximum and no more suitable container has been found than iron, preferably pure iron un'alloyed with other intermetallic constituents or with metalloids such 35 i as carbon, silicon, etc.- A I Heretofore it has been customary, to make the metals reduction chamber, substantially as described in the abovementioned copending application and usually designatedas a reduction bomb, of cold rolled steel or. in. the larger type bombs of drop forgings of steel, which are usually machinedto size.

Oneof the disadvantages of the use of steel orsteel drop forgings has been the expense attending the making of these reduction bombs. Another objection has short life ofthese steel or iron reduction bombs due to excessive surface oxidation and scaling at the temperatureto which they" been the relatively.

1928. Serial No. 272,651.

have been heated and to the fact that two closely contacting metal surfaces tendtobe come welded orbonded together'when sub ected to elevated temperatures approximat I ing 1000 C. v,

A third objection has been that the steel usually contained carbon or silicious impurir ties which in the first run. or two contami nated' the reduced metal powder.

'Afourth objection was found in the fact that on effecting reductions .in the larger sized bombs where a largequantity of metal powders were required on a production basis, difficultyin removing the reduced charge from the bomb? increased proportionally with the size of the bomb, as such a bomb could be made to weigh more than one man could conveniently handle.

Another objection was the cost of replacement and costs of upkeep on the larger bombs. I V

It is one of the objects ofthis invention to provide a reduction chamber substantially non-porous and non-oxidizing which will have relatively long life and low maintenance costs. I

It is also one of the objects of this invention to provide a material for theinside of the reduction chamber which is substantially non-contaminating to the reduced refractory metal powder.

Another object of this invention is to provide a means of providing the interior of the reduction chamber with a removable noncontaminating sleeve in which the reduced and fused charge may be contained.

Another object of this invention is to provide a method wherein the refractory metal I powder is recoveredfrom the fused reduc tion mass in a simple, expeditious and continuous manner. Y Another object is to provide a mechanica arrangement of parts in the assembly of the non-porous non-oxidizing reducing chamber, internal non-contaminating sleeve, reduction charge, so that a substantial vacuum can be obtained within the assembly andmaintained during the heating of the same to the. high temperatures essential to the process and which assembly may be easily and readily taken apart on the completion of the reduction.

Another object'of the invention is to provide a bomb, having its component parts so constructed and arranged that they may be assembled and disassembled with convenience and rapidity.

Other objects of the invention will become apparent from the following description, together with the accompanying drawingsin which: I V

Fig. 1 is a side elevational View of a. bomb embodying the present invention, portions of the bomb being broken away to more clearly illustrate the internal structure *ig. 2 is a view of the under side of the cover of the bomb shown in Fig. 1; and,

form of a protective cap 13. The pe 3 is a plan view the bomb with the cover and stopper removed.

11- 4 l lg.

A bomb constructed in accordance with m invention may comprise achamber preferably in the form of a. cylindrical member closed at one end and having an op ning 10 to'permit the introduction of a c rge therein, The openingll) is provided with aground tapered seat 1 to receive a ground tapered stopper 12. V

For the purpose of applying force to stopper to hold it in llQiIl'lGilCilll: tion to the seat, means are prov 1 d le aof the cap is provided with a'plurs flanges 19 (see Fig. 2) i paced relation and the perimeter or mouth the c .rnber provided with a plurality of ledges 1S dis posed in spaced relation. The cover is so proportioned to permit the oi' the ledges 18 between the flanges 19 by reason of spaces 13 5 when the cover is applied over the mouth or" the chamber, the flanges 19 between the spaces 14" on the chamber. T 0 cover 13 is provided with annular rec s 17 to permit free mover nt of the flanges 19 past the ledges 18 v" rcby the cover n Y given a partal r v ally engage the l L ing the cover against mo vement'along the axis of the chamber.

For the purpose of zigainst'its seat 12 e V w'th a movable member in the form of a threaded rod threaded apert v ranged to coincide substantially with the aigial li e of the chamber non the cover is in position thereon. A rounded end of the rod is so disposed as to be engage-able with a lug 16 integral with the stopper 12. The rod 1 1 is provided with suitable means as a nut 20 for er'iecting aot the threaded rod to actuate the same and apply force to the stopper 12, thus pressing the stopper upon i s seat and locking it in gas tight relation thereto.

According to the present invention the and ary movement to fried n 'es, thus lochabove described bomb is constructed of a nonoxidizing, heat-resistant material as, for example, an alloy of nickel, chromium and iron similar in property to nichrome hardite, etc. Care should be taken that the castings or i'orgings be homogeneous in composition and non-porous.

The same material should be used throughout in the construction of the bomb otherwise the difiercnces in the coeliicient of expansion wouldpermit a separation of one or the other of the parts and the contents of the bomb would be exposed to atmospheric contamination.

An important feature of the present invention consists in the provision of what may be termed a liner or containerZl composed a material non-contaminating with respect to the flux employed in the reduction reac tion as, for example, the liner may be of pure iron. The liner 21 may be snugly or loosely fitted to the inner wall of the chamber. It is preferable, however, to make the liner as shown of such dimensions as tobe easily removable so that it be taken out after the reduction has been effected. i

In practice, the charge to be reduced is tamped down into the pure iron tubing liner and inserted into the reduction chamber and an iron cover may, it desirable, be placed over the mouth of the liner to prevent the reduc tion charge from splattering, spilling, or from being blown out of the liner during the reduction process. The ground tapered stopper 12 is then carefully applied to the tapered seat 12 and slightly turned to bring the surfaces in complete contact and the protective cover 13 is put in place with the lugs 18 and ledges 19 engaged. Tightening upon the bolt 14 will then efiectively lock both the cover and thetapered stopper in position. The bomb is then placed in the furnace, which is preferably of the wire wound resistance type, and heated to 900 to 950 C. for the required length of time. After removing from the furnace and cooling to room temperature the bomb may be opened.

The liner containing the reduced charge may then be removed and the stopper quickly reground to fit the taper after which a second liner with a new charge can be inserted in a relatively short interval of time and a second heating made;

The liner containing a reduced charge may be placed in a large volume of water to dissolve out the calcium chloride content of the charge and to break down the excess calcium remaining. This is made possible by the fact'that the liner (which may be of sub stantially pure iron as Shelby steel) does not become oxidized on the surface during the of water should be employed to counteract the heating efiect, due to the energy of solution of the calcium chloridein the water and to the exothermic reaction of calcium metal with water. The evolution of hydrogen, due to the reaction of the excess calcium with water is suflicientto agitate the body of water so as to do away with the necessity of mechanicallystirring the water during decomposition-of the charge as heretofore practiced. After decomposition the residues are then washed with dilute nitric acid to remove the lime and other soluble salts substantially in a manner as described in the above mentioned copending application.-

In using the above described material in the construction of the bomb, the arrangement of parts thereof and" the removable reliner of non-contaminating metal, the process of preparing difiicultly reducible refractory metal powders has been materially simplified and made more efli cient and the labor, re-

placement and time factors greatly reduced,

Although a preferred embodiment of my invention has been described, it is to be appreciated that there may be many ways of varying both the mechanical construction and the I materials composing the metals reduction bomb without substantially departing from .the nature of my invention but such departures and variations are contemplated as fall within the scope of this invention.

What is claimed is:

A metals reduction bomb composed of a substantially non-oxidizing heat resistant alloy, comprising a chamber having an opening, a tapered stopper for said opening, a seat for receiving said stopper, means for retaining said stopper upon said seat to hermetically seal said chamber and an innerremovable liner for said chamber composed of I substantially pure iron.

In testimony whereof, I have hereunto sub- V scribed my name this 23rd day of April, 1928;

WILLIAM PHILIP KIERNAN. 

